Blade sharpening device



H. l.. HOLLAND ETAL 2,993,312

July 25, 1961 BLADE SHARPENING DEVICE Filed Nov. 7. 195'7 44 w j X34 nvrm'or @Wyman ,f3/,Welland Hcwocl Klon? United States Patent 2,993,312 BLADE SHARPENING DEVICE Herman L. Holland and Harold A. Klatt, Clear Lake, Iowa, assignors to Klaho Manufacturing Company, Inc., Clear Lake, Iowa Filed Nov. 7, 1957, Ser. No. 695,036 6 Claims. (Cl. 51-210) Our invention relates to a sharpening tool and more particularly to a sharpening tool that can be powered by a conventional electric hand drill.

Blade sharpening units are generally very old in the art but these devices known to us have certain serious shortcomings. The greatest shortcoming of these devices is that they cannot be used upon a blade unless the blade is conveniently placed in' a vice or clamp at a location where the operator has free and easy access to the blade. A further shortcoming of the sharpening units known to us is that they must all be operated with both hands even iftheir power is derived from manual, mechanical or electrical means'. All of the mechanical or electrically powered devices are equipped with their own individual power units which adds not only to their cost but also to their difculty in handling and operating. Furthermore, many of these devices are dangerous instrumen-talities when used in the hands of the unskilled.

Therefore, the principal object of our invention isto provide a blade sharpening device. that can easily perform its function, despite the position of the blade.

v A further object of vour invention is to provide a blade sharpening device that can be successfully operated with the use of one hand. y l

y A further object of our invention is to provide a blade sharpening device that can maintain a constant angle of attack on. the blade.` ,5 Y A still further objectof our .invention is .to provide a blade sharpening device that can be powered bya conventional hand electric drill.

Y A still further object of our invention is to provide. a bladeV sharpening device that will protecttheoperator fromthe sharpened blade during the sharpening operation;

A still further object of` our invention is to provide a blade sharpening device that is economical of manufac-r ture, durableV in use, and refined in appearance.

These and other objects will be apparent to .those skilled in the art.

Our invention consists in the construction, arrangements, and combination, of the various parts of the device,` whereby they objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in our claims, and illustrated in theaecomp anying drawings, in which: Y n* I l.

` FIG. l is a perspective views of our device being used on the blade of a ywheel-type forage harvester,

IFIG.. Z'is` va. rear end elevational View of our device; an@ .v. y

isa sectional view of our device taken on line 3 3 of FIG. 2.Y n n vWe have used the numeral 10 to generally designate thesframef ayWheel-type Yforage harvester which is partiallyy shown in FIG. 1 A bearing member V12 is secured thereto in any convenient manner and rotatably supports shaft 14 which in turn is connected to a source of rotational power. The exact details of the forage harvester partially shown in FIG. 1 do not constitute a Fpice ets act toy hold cuttingl blades and 22 in spaced apart parallel relation to ywheel 16.

The numeral 24 designatesthe power shaft of our device. The forward portion 26 of shaft 24 is slightly larger in diameter than the rearward portion 28. The forward end 29 of portion 26 is threaded with left-handed threads and the rearward end 30 of the forward portion is threaded with right-handed threads.

A lug washer 32 is rigidly secured to the center of for'- ward portion 26 of shaft 24. A conventional wheel-type sharpening stone 34 with center hole 36 is slidably mounted on portion 26 and is of suicient thickness to span the distance between lug Washer 32 and the threaded end 29 of shaft 24. 4A washer 38 is conventionally placed' over shaft 24 adjacent the forward side of stone 34 and nut 40 is then placed on the threaded forward end 29 of the shaft 24 to tighten washer 38 and stone 34 against lug washer 32. The center portion of the rearward face' of stone 34 can be recessed at 42 to receive lug washer 32.

A spacer washer 44 is rotatably mounted on shaft 24 adjacent lug washer 32. A guide -46 is rotatably mounted on the portion 26 of shaft 24 and is of sufficient thickness to substantially span the distance from spacer washer 44 to the threaded en d of portion 26 of shaft 24. We have shown ,the guide46 to be frusto-conical in shape. This exact shape is not cri-tical as long as the guide presentsl a straight surface angularly disposed to stone 34.

It `should be noted that the top or forward end of the guide 46 is ladjacent spacer washer 44 and has a slightly greater diameter than the spacer washer.

A ball bearing ring can be mounted within guide 46v to reduce friction between the guide and the portion 26 of shaft 24. A recessed opening 48- is concentrically located in the rearV face of guide v46 and ring 50 is rigidly secured therein. .A core 52 is rotatably mounted within ring S0.and also rotatably mounted on portion 26 of shaft v24. Ball bearings 53 are thereupon located between ring' Ordinarily, the tapered' cutting edges 64 of blades '26 and. 22 can be sharpened only when the blades are removed from the flywheel 16. However, the above described structure of our device will permit the uniform sharpening of the blades 20 and 122 without removing the blades from the. machine.

" The end 58 of shaft 24 can be placed in the chuck 60 Y' of drill62. As shown in FIG. 3, the forward conicalshaped surface of guide 46 is placed against the side of cutting blade 20 which is opposite to the cutting edge 64' of the blade. The sharpening stone 34 is then brought into engagement with cutting edge 64 so that the rearward 1' surface of the stone and the cutting edge of the blade are part of my invention and are illustrated in FIG. 1 to in the same plane. Since the top or forward end of the guide 46. is' larger than spacer washer 44, and since the guide 46 is slightly spaced apart from stone 34, a very ne edge can be created on the lower edge of cutting blade 2i), as s hown in FIG, 3. We have found thatthe above .arrangement of the stone 34, spacer Vwasher 44j and g'uide 46 permits a much better sharpening effectV on' blade 20' than if the guide actually engaged the cutting stone.

As the electric drill 62 is actuated in conventional fashion, the shaft 24 and stone 34 will commence to rotate with the drive shaft of the drill. The drill and sharpening assembly are then moved back and forth along the blade parallel to the blades longitudinal axis. Since guide `46 is rotatably secured to the portion 26 0f 3 shaft 24, the guide will rotate with respect to the blade and will reduce the frictional effect therebetween as the drill and sharpening unit are moved back and forth. It is seen, therefore, that our device canv Ibe used to sharpen blade 20 even though the cutting edge 64 of the blade is only a very short distance from the ywheel 16.

Since portion 28 of shaft 24 is of smaller diameter than portion 26, nut 56 can be removed from the threaded end 30 of Aportion l26 to permit the nut and guide 46 to be slidably removed over the narrow portion 28 of the shaft. This would permit guides of different shapes to be interchanged on our device without also having to remove the cutting stone 34. Of course, stone 34 could be removed by actuating nut 40 in conventional fashion. The `left-handed `threads on end 29 of shaft 24 will prevent the rotation of shaft 24 from loosening nut 40 and stone 34.

Since sharpening stone 34 is detachable from shaft 24 by means of nut 40, and since guide 46 is detachable from shaft 24 by means of nut 56, the positions of the stone and guide can be interchanged. Thus, if space requirements would not permit the sharpening unit to be applied to the blade 20 as shown in FIG. 3, the stone 34 and guide 46 could be removed from the shaft 24. The shaft 24 could thereupon be turned end for end (180), the spacer washer 44 and guide 46 placed on the forward end 29 of portion 2'6 to assume the same position with respect to blade 20, as shown in FIG. 3. The sharpening stone 34 could thereupon be placed on the rearward end 30 of portion 26 with recess 42 adjacent lug washer 32. This arrangement of structure would not change the position of the stone 34, spacer washer 44 or guide 46 with respect to blade 20, but it would permit shaft 24 to be operated from the left-hand side rather than the right-hand side as seen in FIG. 3.

Some changes may be made in the construction and arrangement of our blade sharpening device without departing from the real spirit and purpose of our invention, and it is our intention to cover by our claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We' claim:

1. In a sharpening device, a shaft, a sharpening stone element rigidly secured to one end of said shaft, a guide member rotatably mounted on said shaft adjacent said sharpening stone element, said guide member having an inclined blade supporting surface adjacent the side of said sharpening stone element where said guide member is mounted on said shaft, said blade supporting surface on said guide member adapted to support a straight elongated blade, and the other end ofsaidshaft being extended so as to permit its introduction into the chuck of a portable power tool.

2. In a sharpening device, a shaft, a wheel type sharpening stone element rigidly secured to one end of said shaft, a guide member rotatably mounted on said shaft adjacent said stone element, said guide member having a blade supporting surface adjacent the side of Vsaid stone element where said guide member is mounted on said shaft, said blade supporting surface having shape to present a straight line contact with a fiat surface and to form an angle with said stone element, and the other end of said shaft being extended so as to permit its introduction into the chuck of a portable power tool.

3. In a sharpening device, a shaft, a wheel type sharpening stone element rigidly secured to one end of vsaid shaft, a guide member rotatably mounted on said shaft adjacent said stone element, said guide member having a blade supporting surface adjacent the side of said stone element Where said guide member is mounted on said shaft, said blade supporting surface having shape to present a straight line contact with a at surface and to form an angle with said stone element, a spacer washer on said shaft between said stone element and said guide member, and the other end of said shaft being extended so as to permit its introduction into the chuck of a portable power tool.

4. In a sharpening device, a shaft, a wheel type sharpening stone element rigidly secured to one end of said shaft, a guide member rotatably mounted on said shaft, said guide member having the shape of a frusto-cone, said guide member having a blade supporting surface adjacent'the side of said stone element where said guide member is mounted on said shaft, and the other end of said shaft being extended so as to permit its introduction into the chuck of a portable power tool.

5. In a sharpening device, a shaft, a Wheel type sharpening stone element rigidly secured to one end of said shaft, a guide member rotatably mounted on said shaft, said guide member having the shape of a frusto-cone with the smaller end of said guide member being adjacent said stone element, said guide member having a blade supporting surface adjacent the side of said stone element where said guide member is mounted on said shaft, a spacer Washer on said shaft between said stone element and said guide member, said spacer washer having `a diameter less than the diameter of the smaller end of said guide member, and the other end of said shaft being extended so as to permit its introduction into the chuck of a portable power tool.

blade supporting surface adjacent thev side of said stone element where said guide member is mounted on said shaft, said blade supporting surface having a shape to present a straight line contact with a flat surface and to form an angle vwith said stone element, the other end of said shaft being extended so as to permit its introduction into the chuck of a portable power tool, and means on said shaft whereby said sharpening stone element and said guide member can be selectively removed from said shaft to have their positions thereon interchanged.

References Cited in the file of this patent UNITED STATES PATENTS 332,187 Comstock Dec. 8, 1885 662,629 Rose Nov. 27, 1900 Y719,880 Rose Feb. 3, 1903' 1,092,877 1 Wallace Apr. 14, 1914 1,097,226 Hershey May 19, 1914 1,124,331 -Rodgers Jan. 12, 1915 1,388,882 Paul Aug. 30, 1921 1,801,802 Conyngham Apr. 21, 1931 2,073,861' Wolf Mar. 16, 1937 2,112,695 Forss Mar. `29, 1938 2,211,216 Oster Aug. 13, 1940 2,232,402 Norton Feb. 18, 1941 2,497,217 Hall Feb. 14, 1950 A2,749,677 Burgess June 12, 1956 2,848,852 lRosholt lAug. 26, 1958. 

